[Tripledigits]

I know there's been discussion on the Elise being biased toward understeer from the factory. I also recall reading the factory alignment specs are close to 0 camber in front, with -1.5 to -2 in the rear(??). All the pictures I've seen of cars on the track during review testing show the outside front tire contact patch in desperate need of more front camber. I think that's a big part of the understeer equation. I wonder if anyone on the forum here has optimized alignment (geo) for the track?

Jeff

 

[MattG]

I read something, somewhere, implying just the opposite - that Lotus tuned the suspension to provide the optimum camber angle (defined by providing the largest tire contact patch) at all roll angles. I believe the geometry IS optimized from the factory and wouldn't mess with it.

A slight understeering tendency is not a 'bad' thing, you just have to learn how to manage it. I believe one common technique - and I don't have enough racing experience to speak too knowledgeably about this - is known as trail braking. It's where you're on the brakes (relatively lightly) as you begin to turn in to a corner. This transfers more weight to the front tires, which reduces understeer. You then ease off the brakes and apply the gas, accelerating out of the corner.

I think that Lotus is going to set up this car well from the factory, and that it'll only be a matter of 'learning' the handling of this car to get around this rumored tendency to understeer.

 

[ConeFusion]

Even with a favorable camber curve, I have a hard time believing that zero static camber would give you the best front grip. Even race cars run substantial amounts of camber. They have minimal body roll, and I'm sure that their suspensions are built to provide a good camber curve.

 

[Tripledigits]

When you look at the pictures of the car on the track, and see that the loaded front tire is not perpendicular to the ground, regardless of camber curve or any other factor, you know the car does not have enough camber to develop maximum grip in front.

Maybe that's how Lotus dialed in some understeer for street driving.

Understeer on the track = slow lap times in the dry.

Jeff

 

[LarryB]

Wouldn't be too worried about a bias towards understeer at the limits. Being a mid-engine car, it's much easier to deal with. Below that rather high threshold you'd still be able to use thottle-off to tightened a line (oversteer). If your experience with mid-engine cars, it could take a slight edge off the responsiveness towards the limits. If it's biased towards oversteer, you'd better be quick and know the thresholds it you'd want to be able to "catch" it.

 

[Arno]

I wonder if anyone on the forum here has optimized alignment (geo) for the track?

Lotus has slightly different 'track' settings compared to the normal 'road' setup.

Some of the guys who race Elise's in the UK usually advise a setting like this for track use on standard or uprated suspension:

Front:
Camber -1°
Toe OUT 0°15"

Rear:
Camber -2°
Toe IN from 0°30" to 1°00"

Lotus also has some 'track' settings they use for the LSS and they are similar to this.

-1° camber at the front is about the max you can run on the S2 without modifying (shaving) the hub carrier or mounting plinth on the wishbone.

The toe settings can be reduced (to close to '0') if you change the standard rubber bushes in the wishbones to nylon/nylatron or even rod ends as these will reduce (or almost eliminate) the front-back movement in the wishbones and reduces/stop the toe changes under cornering and brake/acceleration forces.

Take care when reducing rear toe though as you don't want the rear to go to toe OUT under load. This is what early (1991/2) MR2's were infamous for.

The Elise always runs toe OUT at the front to make the turn-in more positive and control the way the car corners better.

Bye, Arno.

 

[LarryB]

Oversteer bias in a mid-engine car is a fine line. It will make it more responsive but harder to deal with at or pass the limits. I'm a long time owner of a '91 MR2T. In '93 they redid the suspension & wheel/tire package to dial out some of the snap oversteer & in turn took a edge off the handling. If your going to set the Elise up more towards oversteer, be ready for some hard spins as you learn what it can do... it may pay off in the long run.

 

[ConeFusion]

I just wanted to take the opportunity to thank Arno and all the other Elise owners from outside the US for sharing their knowledge here. I'm sure that we'll have many more questions once the cars arrive, and I hope that you guys will be around to answer them. It's always much better to learn from people with personal experience than having to figure out everything from scratch.

 

[Tripledigits]

Thanks for the scoop, Arno.

I've always liked a touch toe-in on the rear for high speed stability. It is remarkable how just the smallest amount of toe-out in front can improve turn-in.

Cheers,

Jeff